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91.117 Speed under Class Bravo

ikillbigfoot

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§ 91.117 Aircraft speed.

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(a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).
(b) Unless otherwise authorized or required by ATC, no person may operate an aircraft at or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D airspace area at an indicated airspeed of more than 200 knots (230 mph.). This paragraph (b) does not apply to any operations within a Class B airspace area. Such operations shall comply with paragraph (a) of this section.
(c) No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport or in a VFR corridor designated through such a Class B airspace area, at an indicated airspeed of more than 200 knots (230 mph).
(d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

If ATC notifies you while your being vectored low to a visual you are leaving the class Bravo, do you need to slow to 200, if 2 minutes ago the controller said maintain speed 250? If in the same situation, the controller then advises you (while outside of B) to maintain 250....are you then okay because ATC authorized it, or is 200 kts under Bravo a hard number?
 

avbug

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You posted the regulation, and it's fairly clear.

No person may operate...that means you.

Does the regulation state that ATC can waive this? No. ATC is controlling the class B. When you're advised you're leaving Class B...it's up to you to comply with the regulation. If two minutes ago a Class B controller advised you to maintain 250 knots...that was two minutes ago while you were in class B and you could do that. Now you're going below Class B...and you can't.

If you're in the airspace underlying Class B, then you're bound by the regulation.

Class B is busy airspace. Lots of little airplanes buzzing around under there, trying to avoid the Class B airspace. You're about to join them. Is your chance of recognizing that traffc better at 250 knots or 200?

Notice the other parts of that subparagraph:
91.117(a): "...Unless otherwise authorized by the Administrator..."
91.117(b): "...Unless otherwise authorized or required by ATC..."

Now notice the next part:
91.117(c): "No person may..."

Doesn't leave you a lot of wiggle room there; it's clear. You answered your own question. Can ATC authorize a deviation? The regulation doesn't leave ATC room to do that, or the Admionistrator to do that, or for you to ask. No person may...
 

DrewBlows

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It's the same as 250 below 10,000. If a controller tells you to maintain 290 KIAS at 11,000 and a few minutes later clears you to 8,000, you can't continue to maintain 290 just because the controller told you to.
 

byrmar

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I read an article recently about this topic. The basic message from the author (and I agree) was that this is a regulation that needs to be rewritten or abolished especially if the aircraft are operating on an IFR flight plan. Chances are you would send controllers into a fit if you slowed to 200kts everytime you exited class B for 30 seconds or so. Another point of the article was that it can be sometimes difficult to keep track of exactly were you are (in regard to being in or out of B) when operating in the B airspace. I know you have charts that you can reference, but many times you are already busy enough as it is without having to worry if you are in or out of the airspace. I know sometimes the controllers will inform you when you will exit the airspace. Still, the reg is the reg.
 

pilot125

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Yes, this has been talked about before--at length. I won't comment on what is technically right or wrong, but when I am flying around Chicago on my way to PWK, I tend to ask the controller what speed he/she wants. If they reply, "speed your discretion", I go fast. That reg should be changed. I don't believe I am required to carry VFR sectionals or VFR terminal charts of the whole country.
 

avbug

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I don't believe I am required to carry VFR sectionals or VFR terminal charts of the whole country.

What has that got to do with the question of speed beneath Class B?
 

BenderGonzales

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I agree that on an IFR flightplan this regulation is unrealistic. Furthermore, if your destination is the primary airport in a class "B", the controllers are required to keep you within the confines of class "B" and you shouldn't have to worry about it.
 

atldc9

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I don't think the controllers are required to keep you in the confines on the Class B. Inbound to ATL, you routinely get spit out the bottom or the back side of the Class B. Happens all the time.
 

DrewBlows

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I don't think the controllers are required to keep you in the confines on the Class B. Inbound to ATL, you routinely get spit out the bottom or the back side of the Class B. Happens all the time.

I don't frequent ATL much anymore, but I know that the Class B airspace was expanded last year because it was routine to get vectored beyond 20 miles on downwind and find yourself below Class B. The only reason I even looked at it was because ALPA put out a safety bulletin addressing the issue.
 
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